The present invention relates to filling systems for vehicle fuel tanks and particularly tanks of the type which have a remotely accessible filler tube, for example, of the type accessible through a fuel filler door mounted on the side of the vehicle. Fuel tank installations of this sort are commonly employed on passenger cars and light trucks where it is desired to have the fuel tank filler recessed within the vehicle body and covered by a filler door which blends with the side structure of the vehicle for esthetic or styling purposes.
Vehicle fuel tank filler systems require a positive seal of the filler tube or “neck” when the filler nozzle is removed in order to meet mandatory fuel vapor emission requirements; and, thus it has been the practice to provide a one-way valve, typically in the form of a flapper door valve to close the filler tube when fuel is not being introduced to the filler tube during refueling.
It is known to provide a fuel tank filler tube check valve in the filler tube assembly externally of the fuel tank when the filler tube nozzle receiver is attached to the filler tube upon installation of the tank onto the vehicle during manufacturing of the vehicle. However, this arrangement requires the handling of separate filler tube hose connections and the check valve on the vehicle assembly line and thus increases the number of parts or components to be supplied to the assembly line and the complexity of vehicle assembly.
The problem is further complicated by the fact that present vehicle production utilizes both plastic and metal fuel tanks which require two different types of attachment of the filler tube thereto. Thus, it has been desired to provide a way or means of incorporating a single, fuel tank filler tube check valve which may be employed in a pre-assembled package with a fuel tank of either metal or plastic material without the need for having two different check valve arrangements. Furthermore, it has been desired to provide such a fuel tank filler tube check valve arrangement which will readily accept a siphon tube or hose therethrough for removing fuel from the tank in the event that service or replacement of the fuel tank is required.
It has also long been desired to provide a vehicle fuel tank with the filler tube assembly attached thereto and the one-way check valve incorporated therein as a complete tank subassembly ready for installation on the vehicle.